Avionics Update: Collins tests first multi-mode microwave receiver

The first fully integrated multi-mode receiver (MMR) for use with microwave landing systems completed a series of successful test flights recently. MMR maker Rockwell Collins said the tests would lead to certification early next year. TSO approval for the MMR unit should be in hand by the end of the first quarter, with initial deliveries starting soon after to the U.S. Air Force. European nations, led by the UK and the Netherlands, have embraced MLS for its ability to increase capacity at busy airports. Experts say MLS offers an approximate doubling of normal capacity compared with aircraft flying Category III ILS approaches. Unlike MLS, additional spacing is required because aircraft on final during ILS approaches cause signal multipath disturbances to the localizer beam, which, depending on the shape and size of the aircraft on approach, can last many seconds, or even minutes, before becoming stable again. The recent flight tests of Collins’ MMR included more than 100 MLS approaches at 12 airports in the U.S. and Europe. The approaches were flown to Cat IIIb minimums. Collins said its MMR is fully interoperable with ILS, VOR, MLS, GPS and GLS.